DE102011103749A1 - Multi-channel detection device for detecting field components of magnetic field vector produced by magnetic field line camera, has sensor chips whose respective associated Hall-sensors form separate measuring channel - Google Patents

Abstract

The device has sensor chips (10,20) formed in silicon substrate (1). The chips have equal number of Hall sensors (11,12,21,22) on active surface along a line specific interval. The sensor chips on the carrier are arranged, such that Hall sensors of sensor chips are aligned orthogonally to each other. The respective associated Hall-sensors of sensor chips form a separate measuring channel.

Description

The present invention relates to an integrated multi-channel detector device for detecting the field components of a magnetic field vector.

Integrated magnetic field sensors that use the Hall effect to detect a magnetic field, for example, have a square, plate-shaped electrical conductor, on whose four narrow sides or corners each have a contact electrode is provided. The contact electrodes are connected to an electronic circuit. In each case two contact electrodes arranged opposite the plate-shaped electrical conductor are combined to form a pair of contact electrodes. The electrodes of a pair of contact electrodes are each arranged opposite to the electrical conductor. Via the first contact electrode pair, a current for generating a current flow through the plate-shaped electrical conductor can be impressed. The second contact electrode pair serves as a measuring contact electrode pair, with which the Hall voltage can be tapped, which arises in an applied magnetic field perpendicular to the direction of the impressed current flow in the conductive region of the magnetic field sensor.

For example, in Hall sensors integrated in CMOS technology, the electrically conductive region consists of an n-doped semiconductor region on a p-doped substrate of a silicon chip. In so-called laterally integrated Hall sensors, the plate-shaped electrically conductive n-doped region extends parallel to the surface of the semiconductor chip. By CMOS technology several Hall sensors including an associated electronic circuit can be monolithically integrated in a chip, so that Hall sensor modules, each with several parallel measuring channels can be realized, which are suitable, for example, by baying for a magnetic field-sensitive line sensor.

A disadvantage of a line sensor with laterally integrated Hall sensors is that only a component of a magnetic field vector acting perpendicular to the surface of an integrated Hall sensor module can be detected.

The present invention has thus set itself the task of providing a Hall sensor module with multiple channels, which allows a multi-dimensional detection of a magnetic field vector.

To achieve this object, the present invention proposes a multi-channel detector device for detecting the field components of a magnetic field vector in at least two spatial directions. This detector device comprises at least a first sensor chip and a second sensor chip and a carrier. The first sensor chip and the second sensor chip each have an equal number of at least two Hall sensors which are arranged on an active surface of the respective sensor chip along a line at intervals from each other. The first sensor chip and the second sensor chip are arranged on the carrier such that the Hall sensors of the first sensor chip are aligned in each case orthogonal to the Hall sensors of the second sensor chip. Each Hall sensor of the first sensor chip is assigned to a separate Hall sensor of the second sensor chip. The respective associated Hall sensors of the first sensor chips and of the second sensor chip form a separate measuring channel.

Advantageously, the Hall sensors of the first and second sensor chips are each arranged at regular intervals along the line to each other.

An advantageous embodiment provides that the detector device comprises at least two third sensor chips, which are designed to detect a further magnetic field component in a third spatial direction. The third sensor chips each have at least one Hall sensor and are each arranged on the carrier in such a way that every third sensor chip is assigned to one of the measuring channels.

The present invention provides with this preferred embodiment a detector device for the three-dimensional detection of a magnetic field, wherein the magnetic field vectors can be scanned in a spatially narrow range at least two channels.

The measuring channels preferably have an equidistant distance from each other, so that a 3D magnetic field-sensitive line sensor with a constant local scanning can be provided with the detector device.

All Hall sensors are preferably of similar construction.

Particularly advantageously, all Hall sensors are arranged substantially in a common plane, which is parallel to the plane of the carrier. The magnetic field vectors can thus be detected in all spatial directions as well as in all spatially-spaced measurement channels with substantially comparable tolerances.

The sensor chips may include a silicon substrate in which the Hall sensors with at least a part of an evaluation by means of CMOS technology monolithic integrated.

Due to the monolithic integration, it is possible, for example, to provide a plurality of Hall sensor elements for each individual Hall sensor, for example also with different sensor geometries, which enable offset compensation in conjunction with the electronics.

In a further preferred embodiment of the invention, the carrier can also contain a silicon substrate in which at least part of an evaluation electronics are monolithically integrated by means of CMOS technology. This enables an integrated signal processing or an adjustment of all sensors of a respective measurement channel and, if necessary, an adjustment of the individual measurement channels with each other.

The carrier and the sensor chips of the detector device can be electrically connected to one another by means of bonding wires, conductive adhesive and / or solder joints.

According to the invention, a hybrid integrated component is provided with a detector device. The device comprises a number of monolithically integrated CMOS Hall sensor chips, which are arranged on a common carrier and allow the construction of a magnetic field-sensitive line sensor with a resolution in the range of, for example, 1 mm as line spacing.

The invention also encompasses a magnetic-field-sensitive line scan camera with at least one multi-channel detector device described above, which is particularly suitable for metallurgical analysis methods, ie. H. in materials science, is suitable.

Such a magnetic field-sensitive line scan camera is suitable, for example, for checking welded joints in pipes or for detecting defects or rust on ferromagnetic materials.

A detector device according to the invention will be described in detail below with reference to an exemplary embodiment of a Hall sensor module with reference to a figure.

The figure shows a five-channel 3D Hall sensor module for detecting the field components of the field vectors of a magnetic field in all three spatial directions.

The Hall sensor module exemplified in the figure comprises a carrier 1 which is advantageously made of a silicon substrate. The carrier 1 consists essentially of a silicon chip, on the surface of which at least one metallization plane is provided. In the drawing are exemplary the contact fields 18 and 38 represented as an essential part of the metallization level. Furthermore, conductor track structures can be realized with the metallization levels, which are not explicitly shown in the figure. On the surface of the carrier 1 For example, a passivation oxide may be provided in the areas of the contact pads 18 and 38 has corresponding contact window. The illustrated contact fields 18 and 38 For example, the bond pads may provide electrical connections through bond wires, glue or solder joints.

The silicon surface of the carrier 1 may include, for example, a CMOS technology integrated circuit, with the measurement signals of the Hall sensor module can be processed electronically.

On the carrier 1 is a number of silicon chips 10 . 20 and 30 arranged by adhesive bonding, for example by means of adhesive to the surface of the carrier.

The first silicon chip 10 FIG. 10 illustrates an integrated sensor microsystem that includes, by way of example, a number of five Hall sensors. The Hall sensors are identified by the reference numerals 11 . 12 . 13 . 14 and 15 characterized square structures on the active surface of the first silicon chip 10 indicated. The sketched Hall sensors may each comprise a plurality of interconnected Hall sensor elements. Different Hall sensor elements, which differ from one another for example in their spatial orientation and / or in their geometric shapes or dimensions, can be used to compensate for different measurement errors (eg offsets).

The Hall sensors may each be associated with an integrated circuit in the chip surface, which may have a signal amplifier in addition to an interconnection for offset error compensation. Such an integrated circuit for signal conditioning is not shown for reasons of representability and better clarity in the figure.

On the surface of the illustrated silicon chip 10 is a number of contact surfaces 16 to recognize that for the electrical contacting of the silicon chip 10 serve.

The surface of the carrier shown in FIG 1 is aligned parallel to the plane defined by the x and y axes of the coordinate system. The five Hall sensors 11 . 12 . 13 . 14 and 15 of the first silicon chip 10 are thus uniform along an x-directional line Spaced apart. In addition, as can be seen from the figure, the Hall sensors are aligned parallel to the xy plane, so that the field components of the magnetic field vectors acting in the z direction can be detected in parallel by the x-directional Hall sensors.

The first silicon chip 10 thus forms an extended in the x-direction five-channel detector device for detecting the z-field components of a magnetic field.

The first silicon chip 10 is on the back of the silicon carrier 1 attached. The contact surfaces 16 on the surface of the first silicon chip 10 are thus parallel to the contact surfaces 18 on the chip surface of the carrier 1 aligned. The first silicon chip 10 can with the carrier 1 be electrically connected via bonding wires. During bonding, the bonding tool used for this purpose can be spaced apart in the Z direction and aligned parallel to one another by contact surfaces of the first silicon chip 10 and the vehicle 1 each be placed horizontally. The height difference in the z-direction can be compensated for by the loop in the bonding wire, as in conventional packaging in an IC package.

The second silicon chip 20 is essentially identical to the first silicon chip 10 built up. Unlike the first silicon chip 10 is the second silicon chip 20 with respect to a longitudinal axis rotated by 90 ° on the support 1 arranged. The to the contact surfaces 26 on the surface adjacent elongated side of the second silicon chip 20 is therefore correspondingly for a corresponding bonding process on the support 1 prepared.

The Hall sensors 21 . 22 . 23 . 24 and 25 are in the y-direction parallel to the Hall sensors 11 . 12 . 13 . 14 and 15 of the first silicon chip 10 shifted and arranged at equal intervals along an x-directional line.

The surface of the second silicon chip 20 is aligned parallel to the xz-plane of the coordinate system defined in the figure and thus orthogonal to the surface of the first silicon chip 10 , The Hall sensors 21 . 22 . 23 . 24 and 25 are thus suitable for detecting the y-directional field components of magnetic field vectors.

The electrical contacting of the second silicon chip 20 takes place via the contact surfaces 26 perpendicular to a corresponding contact plane of the carrier 1 are arranged. This contact level is through the first silicon chip 10 hidden and is therefore not visible in the figure. An electrically conductive connection between the associated contact surfaces of silicon chip 20 and carriers 1 can be ensured for example by a conductive adhesive or by solder joints.

The second silicon chip 20 thus provides an extended in the x-direction five-channel detector device for detecting the acting in the y direction field components of magnetic field vectors.

The Hall sensors of the first and second silicon chips 10 and 20 are essentially in a common plane that is parallel to the plane of the wearer 1 lies, arranged. That is, the Hall sensors aligned in the xz plane 21 . 22 . 23 . 24 and 25 of the second silicon chip 20 have in the z-direction at least on average the same distance from the carrier 1 like the xy-direction Hall sensors 11 . 12 . 13 . 14 and 15 of the first silicon chip 10 ,

The first silicon chip 10 and the second silicon chip 20 act together and thus form a five-line detector device, with the acting in the y and z direction field components of magnetic field vectors can be detected simultaneously.

For detecting a third, ie acting in the x-direction field component in the Hall sensor module shown in the figure, five further silicon chips 30 each provided with an integrated Hall sensor 31 . 32 . 33 . 34 and 35 have. The active surfaces of the five other silicon chips 30 are each related to the active surfaces of the first 10 and the second 20 Silicon chip arranged orthogonally.

The Hall sensors 31 . 32 . 33 . 34 and 35 are aligned according to the coordinate system of the figure parallel to the plane defined by the y- and z-axis, and thus formed for detecting the acting in the x-direction field components of a magnetic field vector. Furthermore, the five silicon chips 30 such on the surface of the carrier 1 aligned that the respective Hall sensors 31 . 32 . 33 . 34 and 35 along a line oriented in the x-direction form a uniformly spaced arrangement.

The five silicon chips 30 Thus, provide an extended in the x-direction five-channel detector device for detecting the acting in the x-direction field components of magnetic field vectors.

The electrical contacting of the five silicon chips 30 takes place via the contact surfaces 36 perpendicular to the contact surfaces 38 of the carrier 1 are arranged. An electrically conductive connection between the associated contact surfaces of silicon chip 20 and carriers 1 can be ensured, for example, by a conductive adhesive or by solder joints (eg solder bumps). These conductive connections are each in the areas 37 formed, in which the contact surfaces 36 and 38 abut.

The Hall sensors of the five silicon chips 30 each have the same distance to the Hall sensors of the second in the y direction 20 or the first silicon chip 10 on.

The Hall sensors of the first and second silicon chips 10 and 20 as well as the five other silicon chips 30 form an extended in the x-direction five-channel detector device with which the field components of magnetic field vectors in the x-, y- and z-direction can be detected. Each Hall sensor of the first silicon chip 10 is with a sensor of the second silicon chip 20 and a Hall sensor from the five other silicon chips 30 each combined into a measuring channel. Each of these measuring channels thus comprises three Hall sensors for detecting in each case one field component of magnetic field vectors. The three Hall sensors are preferably arranged along a line oriented in the y-direction with uniform distances from one another.

The five measuring channels of the illustrated Hall sensor module which are arranged parallel to one another in the x-direction form a five-channel detector device which permits a five-line scanning of a magnetic field which is extended in the x direction. The Hall sensor modules can be designed for a baying in a straight or curved plane, preferably with the same distance between the sensors and with each other to the adjacent module.

All Hall sensors are arranged substantially in a common plane that is parallel to the xy plane. The surface-integrated Hall sensors of the first silicon chip 10 are aligned parallel to the xy plane while the Hall sensors of the second silicon chip 20 and those of the five other silicon chips 30 each orthogonal in one of the Hall sensors of the first silicon chip 10 defined level lie.

The hall sensor module shown as an example is preferably suitable as a multi-channel detector device for a magnetic field-sensitive line scan camera. This can be used, for example, for metallurgical analysis methods. For scanning a ferromagnetic material, the Hall sensor module shown can be moved in the y-direction over a surface to be scanned, so that a magnetic field in five lines, which are uniformly spaced in the x-direction, is scanned. A local, or in motion temporal offset in the detection of the x, y and z components, by the spaced arrangement of the silicon chips 10 . 20 and 30 conditional, can be electronically compensated.

Through the monolithic integration of the Hall sensors into the silicon chips 10 . 20 and 30 and in connection with the assembly and connection technique (AVT) by means of adhesive bonding of the components on the silicon support 1 can be achieved with the illustrated Hall sensor module spatial resolutions with a line spacing of 1 mm. The Hall sensors of all silicon chips 10 . 20 and 30 are each integrated as a lateral Hall sensors in the chip surface and preferably have an identical design. The orientation of the sensors to the spatial directions to be detected is particularly advantageous due to the spatial orientation of the silicon chips 13 . 20 and 30 on the surface of the carrier 1 ,

Claims (10)

Multi-channel detector device for detecting the field components of a magnetic field vector in at least two spatial directions (y, z), wherein the detector device comprises at least one first sensor chip ( 10 ) and a second sensor chip ( 20 ) as well as a carrier ( 1 ), wherein the first sensor chip ( 10 ) and the second sensor chip ( 20 ) each have an equal number of at least two Hall sensors ( 11 . 12 ; 21 . 22 ) on an active surface of the respective sensor chip ( 10 . 20 ) are arranged along a line at intervals, and wherein the first sensor chip ( 10 ) and the second sensor chip ( 20 ) on the support ( 1 ) are arranged such that the Hall sensors ( 11 . 12 ) of the first sensor chip ( 10 ) to the Hall sensors ( 11 . 22 ) of the second sensor chip ( 20 ) are each aligned orthogonal to each other, each Hall sensor ( 11 . 12 ) of the first sensor chip ( 10 ) a separate Hall sensor ( 21 . 22 ) of the second sensor chip ( 20 ), wherein the respective associated Hall sensors of the first sensor chips ( 10 ) and the second sensor chip ( 20 ) form a separate measuring channel. Detector device according to claim 1, characterized in that the Hall sensors ( 11 . 12 ; 21 . 22 ) of the first and second sensor chips ( 10 . 20 ) are each arranged along the line at regular intervals from each other. Detector device according to one of the preceding claims, characterized by at least two third sensor chips ( 30 ) for detecting a magnetic field components in a third spatial direction, wherein the third sensor chips ( 30 ) at least one Hall sensor ( 31 . 32 ), and wherein the third sensor chips ( 30 ) on the support ( 1 ) are arranged such that every third sensor chip ( 30 ) is assigned to one of the measuring channels. Detector device according to one of the preceding claims, characterized in that the measuring channels have an equidistant distance from each other. Detector device according to one of the preceding claims, characterized in that all Hall sensors ( 11 . 12 ; 21 . 22 ; 21 . 32 ) are constructed identically. Detector device according to one of the preceding claims, characterized in that all Hall sensors ( 11 . 12 ; 21 . 22 ; 31 . 32 ) substantially in a common plane parallel to the plane of the carrier ( 1 ), are arranged. Detector device according to one of the preceding claims, characterized in that the sensor chips ( 10 . 20 . 30 ) contain a silicon substrate in which the Hall sensors ( 11 . 12 ; 21 . 22 ; 31 . 32 ) are monolithically integrated with at least part of an evaluation by means of CMOS technology. Detector device according to one of the preceding claims, characterized in that the carrier ( 1 ) contains a silicon substrate, in which at least part of an evaluation by means of CMOS technology is monolithically integrated. Detector device according to one of the preceding claims, characterized in that the carrier ( 1 ) and the sensor chips ( 10 . 20 . 30 ) are electrically connected to each other by means of bonding wires, conductive adhesive and / or solder joints. Magnetic field-sensitive line scan camera for metallurgical analysis methods with at least one multi-channel detector device according to one of the preceding claims.

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